Rather than removing your day scope and mounting a dedicated thermal riflescope in its place, a clip-on attaches directly in front of your existing scope's objective lens. Flip it into place and you're looking through your scope in thermal; flip it away (or remove it) and you're back to your normal day optic — with the same reticle, the same magnification, and the same zero you already had dialled in.

This makes a clip-on the practical choice if you already own a scope you trust and don't want to give up its glass quality, reticle, or zero just to add thermal capability — you're adding a genuine new capability to your existing setup, not replacing it.

The Pulsar PSP-B Ring Adapter isn't a separate product competing with the Krypton 2 — it's the mounting hardware that actually attaches the clip-on to your scope's specific objective lens diameter. Check your scope's objective size before ordering to confirm you're getting the correct adapter for your setup.